Type-writing machine.



W. F. HEL MOND.

\TYPE WRITING MACHINE.

APPLICATION FILED M09, 1912.

Patented July 27, 1915.

UMIEE era s earner ent ies.

WILLIAM F. HELMOND, OF HARTFORD, CONNECTICUT, ASSIGN'OR TO UliTDERWOOD TYPEWRITER COMPANY, OF NEW YORK, N. 'Y., A CORPORATION OF DELAWARE.

TYPE-WRITING MACHINE.

master;

Specification of Letters Patent.

Patented July 27, 1915.

I Application filed December 9, 1912. Serial No. 735,611.

To all whom it may concern:

Be it known that I, WILLIAM F. HELMOND, a citizen of the United States, residing in Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Type- VVriting Machines, of which the following is a specification.

My invention relates to means for connecting and disconnecting the platen and line-space wheel in typewriting machines.

The primary object of my invention is to provide a simple and practical device of the character above indicated which will effectually prevent slipping or relative rotation of the platen and line-space wheel while they are connected to rotate together.

The requirements for a practical clutch device between the platen and line-spacer are exacting. In the first place, it is essential that there shall be no slipping whatever, which necessitatesa clutch that is powerful alid positive in action. At the same time it is important that the means to apply and release the clutch shall operate with ease 1 and without any tendency to throw the platen out of its adjusted position relative to the line-space wheel.

The present invention is designed to meet the above requirements, and to provide a construction embodying various features of novelty and utility as Will appear more ful y hereinafter in connection with the detailed description.

An important feature of my invention is found in the use of a plurality of gripping jaws or grips in the clutch, whereby the gripping action is multiplied and slipping effectually prevented. In the patent to Nev, No. 979,991 of December 27, 1910, a split ring in the clutch is employed. In the present invention I use more than one gripping jaw, while at the same time a single cam is required to release or expand the gripping jaws. The symmetrical arrangement of the gripping jaws on opposite sidesof the axle also overcomes the usual tendency to rotate the line-space wheel through a slight angle when the clutch is being operated.

My invention also provides a toggle conncction between the clutch jaws and the operating levers, .Whereby a very powerful gr pping action is secured.

A further feature of the invention residesin the use of a latch to automatically lock the clutch-operating cam against accidental movement toward a released position. A lost motion connection between the cam and the thumb-piece for actuating the'same permits the latch to be released during the preliminary movement of said thumb-piece to release the clutch.

" means therefor. Fig. 4 is an enlarged detail view of parts shown in Fig. 3. Figs. 5 and 6 are elevation views showing the clutch in its released and applied positions respectively. Figs. 7 and 8 are detail views of a latch in its released and locking positions respectively.

The usual cylindrical platen 1 is fixed to the axle 2 iournaled in the ends of a platen frame A lever 4 is adapted to operate a slide 5 which carries a pawl 'Z-coiiperating with the line-space wheel 6, the latter being held in operated position by the usual de- 'tent 8. The line-space wheel 6 is mounted for rotation on the axle 2 to permit independent adjustment of the platen, but under normal working conditions is securely held against such rotation' by my improved clutch, as will presently be described. Between the platen and the line-space wheel is a collar 9 adjustably secured to the shaft by a set screw.

The clutch comprises a clutch part 10 rigidly secured to or formed integral with the Wheel (3, and provided with an annular flange 11 forming a drum. Within the flange 11 is a disk 12 fixed to the axle and having a hub extension 13 forming a bearing for the part 10 and Wheel 6. clutch members in the form of awe or grips 14 are adapted to be sprung into frictional Expansion engagement with the inner periphery of the flan e 11. The grips 14 are preferably of annular structure, each being a segment of a ring, and are made of spring steel and are curved to conform to the bearing surface of the drum throughout their length except at their ends which are bent inward at an angle to saidbearing surface. two grins 14 thus form an expansion ring having a plurality of separate expansible segments each adapted to besprung into lengthwise engagement with the flange 11 to grip the same. I

' A block 15 is rigidly secured to the disk 12 by rivets 1G or other suitable means, and is formed with hearing notches '17 for the ends of the grips 14. For the purpose of adjusting the grips 14, the block 15 is split and threaded to receive an adjusting screw 18, the screw-opening being countersunk or tapered so that the block 15 may be expanded by setting up the screw. This provides for an accurateand fine adjustment of the grips 14.

The clutch grips.14 are expanded into on the grips 14. The levers are provided with bearing recesses for the fulcrum pin. The ends of the grips 14 engage in notches 22 formed in the levers 20. It will be observed that the direction of each bearing notch 22 from the fulcrum pin is substantially at right angles tothe general direction of the lever, so that the levers 20 are in effect bell crank levers, and when the levers 20 are spread, the bearing points 22 are carried upward. By reference to Fig. 5, it will be seen that the upper end of each grip 14 is bent away from the flange 11 at a point 23 which is so locatedrelatively to the fulcrum 21 and bearing point 22 that the latter isslightly below the line joining the point 23 with the fulcrum 21. There-is thus formed a toggle comprising the horizontal arm of the lever 20'and the deflected portion of the grip 14.

It will now be apparent that an outward pressure on the lever 20 will cause a multiplied pressure in an upward direction at the bearing point 22, which, owing to the toggle arrangement, will result in a very powerful outward pressure at the point 23. This pressure applied in an endwise direction to the clutch grip 14 causes it to powerfully grip the flange 11. As ,a very small movement of the grip 14 is sufficient to carry it from released to gripping position, the power applied to the levers 20 is multiplied to an extent to secure a very effective and reliable clutching action. By setting up the screw 18 the block 15 is spread so that the points at which the grips abut said block are moved outward and reduce the distance from The said points to the points of contact with the levers 20, thus increasing the gripping power of the grips. A cover plate 35 is secured to the flange 11 and prevents displacement of the clutch jaws 14 and levers 20.

I am aware that it is not new to employ a, split ring in a clutch between the linespace wheel and platen of a writing machine, as shown for example in said patent to Ney, 979,991, but the form of expansion clutch member 14 and operating means therefor as disclosed in the present application I believe to be new, effective and prac tical.

Another important feature of the present invention resides in the use of a plurality of expansion members combined in a single clutch and controlled and operated by a single operating device as hereinafter described. I have found that a clutch member in the form of a half ring, as the grip 14, is fully as effective as the usual split ring extending nearly around the clutch, and when formed and applied as above disclosed, is much more effective. It also permits the use of two expansion grips 14 in the same clutch and located in the same plane. This provides a symmetrical structure that permits the use of a single operating device which is simple and effective, and which automatically distributes the gripping pressure equally between the two grips. It will thus be seen that much more than a mere duplication of parts is involvech The mechanism for operating the clutch will now be described. A thumb-wheel 25 is mounted on a metal sleeve or hub 26 fixed on the end of the platen axle 2. The hub 26 is formed with cylindrical openings parallel with the axle to receive rods 27, 2S and 29 slidable in said openings. A thumbpiece 30 is secured to the outer ends of therods 27, 28. A clutch-operator 31 is mounted on the axle 2 between the clutch and the thumb-wheel 25, and is adapted to be moved longitudinally of the axle by-means of the thumb-piece 30 and rods 27, 28. Each of said rods is formed with a reduced portion or neck 32 and a head 33 at the inner end of the rod. The right hand end of the operator 31 forms a hollow cylinder or barrel to receive the heads 33 which engage behind a flange 34 formed at the end of said operator. This arrangement permits a relative longitudinal movement of the operator 31 and the rods 27,28, for a purpose which will presently be described. The inner end 136 of the operator 31 is tapered and when a locking rod, is connected to the operator 31 by means of a head 37 which engages behind the flange 34. It will be noted that the space between the head 37 and the body to locking position. From the neck 42 therod is tapered outwardly to form a cam surface for lifting the latch.

The complete operation of the clutch mechanism may be briefly reviewed as followsz In Figs. 1, 2, 3, 5 and 7, the parts are shown in the position assumed when the thumb-piece 30 has been pulled outward to release the clutch and permit the platen to be rotated independently of the, line-space wheel. To connect the line-space wheel and platen, the thumb-piece 30 is pushed inwardly. The initial movement carries the rods 27, 28, inwardly to take up the lost motion and brings the heads 33 up solidly against the operator 31. The continued inward movement of the thumb-piece carries the cam 36 inward through an opening 35 in the plate 35. The cam 36 entering between the levers 20 forces them apart and operates theclutch as heretofore explained. The locking rod 29 is carried inward with the operator 31 and passes beyond the latch 38 as the operator 31 completes its movement. The neck 42 is now opposite the latch and permits it to drop behind the locking rod, as shown in Figs. 4 and 8. Thecam 36 is thus positively prevented from slippingback and locks the clutch in operated position. There is therefore no possibility of the clutch accidentally working loose and permitting slippage between the platen and line-space wheel. To release the clutch the thumb-piece 30 is pulled outward. The lost motion connection permits] the rod 28 to move outward and lift the .latch 38 to free the locking rod 29 before the pull on the 'gagement with the drum.

toggles between the fulcrum pin and said ring, and means to operate the levers.

2. In a typewriting machine, the combination of a platen and axle, a line-space wheel loose'on the axle, and clutch mechanism com- '10 prisinga member secured to said wheel and formed with an internal circumferential bearing surface, a member fixed to 'theaxle, gripping devices adapted to engage said bearing surface and bearing at one end '15 against said member, and means between the other ends of said gripping devices to spread them into gripping engagement with said bearing surface.

3. In a typewriting machine, the combination with a roller platen and axle, of a lines'pa-ce wheel loose on the axle, a drum secured to the said wheel, a disk within the drum and fixed to the axle, a bearing block carried by the disk,vresilient grips curved to conform to the inner periphery of the drum and each having an end bearing against said block, and means between the opposite ends of the grips to spread them into en- 4. In a typewriting machine, the combination with a roller platen and axle, of a linespace wheel loose on the'axle, a drum secured to said wheel, a bearing member within the drum and having a fixed connection with the axle, spring grips curved to conform to the inner periphery of the drum and having their ends'bent inwardly, one end of each bearing against said bearing member, levers'between the other. ends of the grips, and means to operate the levers.

5. In a typewriting machine, the combination of a roller platen and axle, a line- 'space wheel loose on the axle, a drum secured to the wheel, expansible grips within the drum, bell crank levers to operate said grips and having armsstraddling the said axle, a cam wedge mounted on the axle and movable longitudinally thereof to operate the levers, and means to actuate the cam wedge.

6. In a typewriting machine, the combination of a roller platen and axle, a line-space wheel loose on the axle, a elutch'to connect the wheel and axle, a clutch-operating de vice mounted on the axle and slidable longivice, and then actuate the clutch-operating device to disconnect the platen and linespace-wheel while the latch is held withdrawn.

7. In a typewriting machine, the combination of a roller platen and axle, a line-space wheel loose on the axle, a clutch for connecting the wheel and axle, a clutch-operating tion of a roller platen and axle, a line-space wheel loose on the axle, a clutch for connecting the wheel and axle, a clutch-operator movable longitudinally of the axle, means to automatically lock said operator in operated position, a manual device to move said operator into and out of operated position, and

' means associated with the manual device to automatically release the lock.

9. In a typewriting machine, the combination of a roller platen and axle, a line-space wheel loose on the axle, a clutch for connecting the wheel and axle, a clutch operator movable longitudinally of the axle, means to automatically lock said operator in operated position, a manual device to actuate said operator and having a lost motion connection therewith, and means operated by said manual device to release the locking means while the lost motion is being taken up in retracting the manual device.

10. In a typewriting machine, the combination of a roller platen and axle, a linespace wheel loose on the axle, a clutch for connecting the wheel and axle, an operator mounted on the axle and movable longitudinally thereof to operate the clutch, a latch movable into position behind s'aid operator to hold it in operated position. a manual releasing means having a lost motion connection with saidoperator, and means associated with said manual means to retract the latch while the lost motion is being taken up.

11. In a typewriting machine, the combination of a roller platen and axle, a linespace wheel loose on the axle, a clutch for connecting the wheel and axle, a thumbwheel secured to the axle, a clutch-operator mounted on the axle between said thumbwheel and clutch and movable longitudinally of the axle, a latch mounted in the thumbwheel and operable to lock said operator in operated position, and manually operable means extending through the thumb-wheel to operate the latch and clutch-operator.

12. In a typewriting machine, the combination of a roller platen and axle, a linespace wheel loose on the axle. a clutch for connecting the wheel and axle, a thumbwheel fixed to the axle. a clutch-operating cam mounted on the axle between the clutch and thumb-wheel and movable longitudinally of the axle to operate' the clutch. a locking rod connected to the. cam. a latch pivoted in the thumb-wheel in position to engage behind said rod when the cam moved to clutch-operating position. a thumb-- piece, and rods connected thereto extending ate said operator and having a lost motion connection therewith, and means operated by said finger-piece while the lost motion is being taken up to automatically release said locking device.

let. The combination with a platen and line-space wheel, of friction clutch mechanism to connect the platen and line-space wheel, said mechanism comprising a clutch part having a peripheral friction-holding surface, a pair of opposite clutch grips of annular structure curved to conform to the curvature of said surface and extending along said surface, and having their ends adjacent, said grips capable of being bowed by pressure thereon endwise thereof into lengthwise engagement with said surface to grip the same, a finger piece, and a single train of operating devices to spring said grips into frictional holding engagementwith said surface and thereby lock the platen for rotation with the wheel. said train extending from said finger piece to one pair of adjacent ends of said grips, and the other ends thereof being supported against movement.

15. In a typewriting machine, the combination of a platen, a loose line-space wheel. a clutch connection comprising a device ha ving a peripheral friction bearing surface. a

split ring comprising a pair of ring segments curved to conform to the said surface and extending along opposite sides thereof, and having their ends adjacent. said segments capable of being sprung'by pressure applied to the ends thereof into lateral eugagement with the said surface to grip the same, and an operating device having means to apply endwise pressure to adjacent ends of said segments to spring them into gripping engagement with said surface. and thereby lock the line-space wheel to the platen, the other ends of said segments supported against movement.

16. The combination with a platcn and a line-space wheel, of friction clutch mechanism to connect the platen and line-space wheel. said mechanism comprising a clutch part having a. peripheral friction-holding surface. springy grips each of the form of a bow conforming to the curvature of said surface, and extending along said sin-fate,

7 and operating means to apply pressure only to the opposite ends of said grips in a direction lengthwise thereof to compress each grip between said abutment and said operating means and thereby cause it to spring laterally to grip said surface to lock the platen and line-space wheel together.

17. The combination with a platen and line-space wheel, of friction clutch mechanism to connect the platen and line-space wheel, said mechanism comprising a clutch part having a peripheral friction-holding surface, springy grips each in the form of a bow extending along the opposite sides of said surface and curved to conform to the curvature of said surface, means located between adjacent ends of'said grips and forming an abutment for one end of "each grip, operating means between the opposite ends of said grips for applying endwise pressure to said grips to spring them into lengthwise engagement with said surface to grip the same, and adjusting means to vary the position relatively to said operating means of the points of contact vof the grips with the abutments and thereby regulate the pressure of the grips on said surface when operated by. said operating means.

18. In a typewriting machine, the combination with a platen and a loose line-space wheel, of clutch mechanism to connect the platen to the line-space wheel, said mechanism comprising a drum, grips curved to conform to the inner periphery of the drum and extending therealong, said grips each capable of being sprung into gripping engagement with said drum, levers to actuate said grips, and a floating fulcrum for said levers, each of said levers operable to apply pressure to a grip and thereby spring it into gripping engagement with the drum, the re-acting pressure of each grip through its lever being in a direction opposing there-acting pressure of the other grip through its lever, said floating fulcrum being held by said re-acting pressures in an equilibrated position in avhich the re-acting pressures counter-balance each other.

19. In a typewriting machine, the combination of a roller platen and axle, a linespace wheel loose on the axle, a friction clutch to connect said wheel and axle, a clutch-operating device, means to lock said device automatically in position with the wheel clutched to the axle, and a releasing device comprising means operable during the initial movement of the releasing de vice to release said lock, and operable during a further movement to then release the clutch.

20. In a typewriting machine, the combination of a roller platen and axle, a linespace wheel, a friction clutch to connect said wheel and axle, a clutch-operating device movable longitudinally of the axle, an automatic lock operative to hold said device in position with the wheel and axle clutched together, and means to hold the lock inoperative while the wheel is unclutched from the axle.

21. In a typewriting machine, the combination with a platen and a line-space wheel, of a friction clutch to connect the platen and wheel, said clutch comprising a clutch part having a peripheral friction surface, a plurality of cooperating springy friction grips of annular structure, curved to conform to said surface, and means to engage the ends of the grips to spring them endwise into engagement with said surface to grip the same, and a manual device to operate said grips.

22. The combination with a platen and a I line-space wheel, of-friction clutch mechanism to connect the platen and line-space wheel, sald mechanism comprislng a clutch part having a peripheral frictlon holding surface, springy grips of annular structure curved to conform to the curvature of said surface, and extending along said surface, said grips capable of being sprung into and out of lateral engagement with opposite faces of said surface to grip the same, means whereby said grips may be sprung by endwise pressure thereon into frictional holding engagement with said surface, and a single manually-operable device to control the operation of said grips, and thereby determine whether the platen and wheel shall be locked together or releasedfrom each other.

23. The combination with a rotary platen and a loose line-space wheel, of a friction clutch to connect the platen and wheel comprising a clutch part having a peripheral friction surface, a plurality of spring friction clutch grips of annular structure curved to conform to the curvature of said surface and adapted to be bowed or sprung 'into' gripping engagement with different peripheral portions of said surface, actuating means to engage the ends of said clutch grips, to exert endwise pressure thereon to sprlng them into clutching engagement with said surface, a finger-piece movable in the and a loose line-space wheel, of a friction clutch to connect the platen and wheel comprising a clutch part having a peripheral friction surface, a plurality of arc-shaped friction bands lying along said surface, and an operating mechanism for applying pressure to each band in a direction to force the bands into gripping contact with said surface, the re-acting pressure of each band on the operating mechanism being in a direction to oppose that of the other band,

said mechanism free to shift to a position in which said pressures are balanced, thereby automatically equalizing the pressure of said bands on the said friction surface.

25; The combination with a platen axle, a platen fixed thereto and a loose line-space Wheel, of clutch mechanism to connect the platen and line-space Wheel, an operator for said mechanism movable longitudinally of the platen axle to operate the clutch mechanism and thereby lock the line-space wheel to the platen, and a locking device for said operator movable transversely of the axle into and out of position to lock the operator .mechanically in operated position with the line-space Wheel locked to the platen.

26. The combination with a platen and a loose line-space wheel, of friction clutch mechanism to connect the platen and linespace wheel, said mechanism comprising a clutch part having a peripheral frictionholding surface, springy grips each comprising a gripping portion of annular structure curved to conform to the curvature of said surface, and extending along said surface, said grips settable to cause said gripping portions to be sprung into engagement with said surface to grip the same, means forming an abutment or bearing for each grip to prevent movement of one end thereof, and means to operate the grips, the said gripping portion of each grip extending between its abutment and said operating means, the latter operable to force said grips by endwise pressure thereon into gripping engagement with the said surface, and thereby lock the platen and line-space wheel together. b

27. The combination with a platen and a line-space wheel, of friction clutch mechanism to connect the platen and line-space wheel, said mechanism .comprising a. clutch part having a peripheral friction-holding surface, sprlngy grips each of annular structure,'curved to conform to the curvature of said surface and extending longitudinally along said surface, said grips capable of being sprung, by force applied to the ends thereof,'into lateral engagement with said surface to grip the same, means to form a support for one end of each of said grips to ating at the other end of each grip in a direction lengthwise thereof to place the grip under tension between its said support and operatingmeans, and cause it to grip said surface to lock the platen and line-space Wheel together, and a finger-piece having movement of said end, and operating means to apply pressure to the other end of each .grip'in a direction lengthwise thereof, to

compress each grip between its abutment and operating means, and thereby cause it to spring laterally to grip said surface to lock the platen and line-space wheel together.

29. In a typewriting machine, the combination with a rotary platen and a line-space wheel, of a clutch for connecting the platen and line-space wheel, said clutch comprising means forming a peripheral bearing surface, grips extending along opposite sides of said surface, a bearing block against which adjacent ends of the grips abut. operating means to engage the opposite ends of said grips, and move them into frictional holding engagement with said surface, and means to adjust said bearing block to vary the position of the grips relatively to said operating means, and thereby regulate the frictional pressure of the grips on said bearing surface when said operating means is actuated.

30. The combination with a platen and a line-space wheel,. of clutching mechanism for connecting the platen and said wheel comprising a' drum having an internal peripheral bearing surface, a pair of grips extending along opposite sides of said bearing surface, and movable into and out of frictional holding contact with said surface, a split block carried by said drum against which adjacent ends of the grips hear, an operating device for moving the opposite ends of said grips into position to cause them to grip said surface. and an adjusting screw to adjustably expand said bearing block, and thereby change the position of the grips relatively to the operating device, to regulate the pressure with which said grips will engage said surface when moved to gripping position by said operating device.

31. In a typewriting machine, the combination with a platen and a loose line-space wheel, of a drum secured to said whecl'and provided with an internal peripheral friction-holding surface, oppositely disposed separate segments or grips each movable independently of the other and extending along opposite sides of said surface within at the same time apply endwise pressure to.

the said grips to forcethem into frictional gripping engagement with said peripheral surface.

32. The combination with a platen and a.

line-space wheel, of clutch parts to connect the platen and line-space wheel, means forming an abutment for one of said parts, and an adjusting device to engage said means and adjustable to adjust the position of said means. and thereby vary the holding power of the clutch.

33. The combination with a platen and a line-space wheel, of clutch mechanism connecting the platen and line-space wheel, said mechanism comprising clutch parts movable into and out of gripping engagement, means forming an abutment for one of said parts, and ascrew-threaded adjusting device having a portion to bear against said means, said adjusting device adjustable by means of its screw-threaded portion working in a correspondingly threaded socket to vary the position of said abutment.

34. The combination with a platen and a line-space wheel, of friction clutch mechanism to connect the platen and line-space wheel, said mechanism comprising a pair of clutch parts, a spacing means between adjacent ends of said'clutch parts, said means comprising parts expansible or movable toward and from each other, and a screwthreaded device for ad usting said means, said device comprising a portionto'enter between and expand or spread the said parts ofsaid means, said adjusting device adjustable by means of its threaded portion working in a threaded socket, to adjust said spac-' ing means. 1

35. In a typewriting machine, the combination with a roller platen'and axle, of a linespace wheel loose on the axle, a drum secured to said wheel, a disk within the drum and fixed to the axle, grips curved to conform to the inner periphery of the drum, a spacing block between adjacent ends of said grips and against which an end of each grip abuts, means between the opposite ends of the grips to spread them into holding engagement with the drum, said block comprising parts expansible to vary the relative position of the bearing surfaces for the grips, and thereby vary the pressure of said grips against the drum, and an adjusting screw to effect said expansion of the spacing block.

36. 'lhe'combination with a platen and a line-space wheel, of a clutch for connecting the platen and line-space wheel, said clutch comprising a grip, and means forming a frictional holding surface against which said grip may be moved, an operating device for moving the grip into frictional holding engagement with said surface, means forming an adjustable abutment for said grip, and an adjusting screw to engage said means and adjustableto vary the position of the point of contact of the grip and said abutment relative to the operating means, to thereby regulate the frictional holding power with which the grip engages the said surface, when actuated by said operating means.

37. In a typewriting machine, the combination with a rotary platen and a linespace wheel, of a clutch for connecting the platen and line-space Wheel, said clutch comprising means forming a peripheral bearing surface, grips extending along op said bearing surface when said operating means is actuated.

38. In a typewriting machine, the combination with a rotary platen and a line-space wheel, of a clutch for connecting the platen and line-space wheel, said clutch comprising means forming a peripheral bearing surface, grips extending along opposite sides of said surface, a split bearing block against which adjacent ends of the grips abut, operating means to engage the opposite ends of said grips and move them into frictional holding engagement with said surface, and an adjusting screw threaded between the parts of said bearing block and adjustable to spread said parts to vary the position of the grips relatively to said operating means, and thereby regulate the frictional pressure of the grips on said bearing surface when said operating means is actuated.

39. The combination with a platen and a line-space wheel, of clutching mechanism for connecting the platen and said wheel, said mechanism comprising a drum having a peripheral bearing surface, a pair of grips extending along opposite sides of said bearing surface and movable into and out of frictional ,holding contact with said surface, a split block against which adjacent ends of the grips hear, an operating device for moving the opposite ends of said grips into position tocause them to grip said surface, and an adjusting screw, the opposing faces of said block having threaded sockets to receive said screw and in which the screw is said block having threaded sockets or readjustable to expand said bearing block and cesses in its opposing faces to receive said thereby change the position of the grips relascrew, the bearing surfaces of the said socktive to the operating device to regulate the ets and screw being relatively formed to per- 5 pressure with which said grips will engage mit the block to be expanded by adjusting 15 said surface when moved to gripping posithe screw therein. tion by said operating device. \VILLIAM F. HELMOND.

40. In a clutch for releasably connecting Vitnesses: a platen and line-space wheel, the conibina- V. M. P. YORKMAN, a 10 tion of a split block, and an adjusting screw, FRANK A. COOK. 

